Magnetron system for simultaneous transmission and reception



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X 6 May 1939' E. GERHARD 2,159,478

a v v MAGNETRON SYSTEM FOR SIMULTANEOUS TRANSMISSION AND RECEPTION Filed June 6, 1956 INVENTQR ERNST GERHARD /Kg i C l||||||||||||||||||| llig. 2

ATTORNEY .u wlm Patented May 23, 1939 UNITED STATES PATENT OFFICE MAGNETRON SYSTEM FOR SIMULTANEOUS TRANSMISSION AND RECEPTION Ernst Gerhard, Berlin,

Germany, assignor to tion of Germany Application June 6, 1936, Serial No. 83,858 In Germany June 12, 1935 8 Claims.

The present invention relates to an arrangement for magnetron apparatus containing several magnetron discharge tubes. In operation with short waves it often happens that several tubes are required for obtaining sufficient power. Thus, it may be desirable to employ several tubes operated in parallel in a transmitter. Alternatively a transmitter tube and. a receiver tube may be employed in combination in a unified circuit of a transmitter-receiver apparatus. When the transmitter as well as the receiver is to be operated on the magnetron principle, each single tube requires the full input for producing the magnetic fields. When using electro-magnets, a very large weight and high cost are involved. It is necessary to use two magnet cores, two copper windings, and twice the magnetizing current. However, when the tubes operate with permanent magnets, it is only the Weight that needs tobe considered.

According to the invention these drawbacks are overcome in that for all magnetic fields necessary, only a single magnet with several pole shoes is used.

It is known that by increasing the pole surface of a magnet, the magnetic resistance in the air gap decreases. Thus, if for instance four pairs of pole shoes of equal size are used in place of a single pair, the magnetic resistance in the air gap drops to one-fourth. In order to produce a certain field strength in one of the air gaps, the same magnetic force or electro-magnetic power should be applied as in the case of only a single pair of pole shoes. Therefore, it is possible to produce with an original magnet which may be a permanent magnet or an electromagnet, all magnetic fields required.

My invention will now be described in detail, reference being made to the accompanying drawing, in which Figure 1 shows a preferred constructional arrangement of magnetic field producing means having different sets of pole faces each set being for a different purpose; and

Fig. 2 shows an embodiment of my invention in which a coupling arrangement between two magnetron discharge tubes is provided, say, for purposes of relaying received signals into a transmitter circuit, both receiver and transmitter being equipped with magnetron discharge tubes.

Fig. 1 shows by way of example a structure according to the invention. The core I carries the two magnetizing coils 2 and 3. The legs of this magnet terminate in the pairs of pole shoes designated by 4, 5 and I0. Between poles 4 the field for the magnetron tube 1 is produced. The field between 5 actuates the tube 6, and the poles Ill form the magnet of the rotating coil instrument II. The intensity of the fields for the two tubes 6 and I can be controlled by varying the iron cross-section by means of the slides 8 and 9. The magnetizing coils 2 and 3 may be energized by any suitable source of direct current as indicated, for example, by the battery B.

It is obvious that the electro-magnet I, 2, 3 may also be replaced by a permanent magnet, and that the number and shape of the pole shoes may be modified at will. There also exists the possibility of combining the field of an existing loudspeaker with the field producing means for other apparatus such as magnetron discharge tubes, use being then made of diiferent sets of pole shoes like those indicated at 4, 5 and I0 in Fig. 1.

Different tubes and of greater number may obviously also be provided and each tube may fulfill an entirely different function. Thus for instance tube 6 may be connected as transmitter tube and I as receiver tube. The transmitter tube can now be modulated with the demodulated speech current of the receiver tube. In this way a very simple relay station is obtained which eventually does not require servicing. A principal circuit is shown by way of example in Fig. 2. The speech current of tube I connected as receiver tube, is superposed by means of the transformer I2 on the plate current of the transmitter tube 6 eventually after preceding amplification, so that 6 sends out the message received in I, and this possibly on a different wave.

In one embodiment in my invention as shown in Fig. 2 the magnetron tube I may be caused to demodulate signals collected on a dipole antenna consisting, for example, of antenna arms I5 each associated with one of the complementary anodes II within the tube. The cathode of the tube is shown at I6. According to well known practice, the anodes may be fed with suitable direct current potential from a source 2| through a bridge member 22 which is preferably positioned to include a nodal point in the resonant circuit formed by the dipole antenna system I5 and the anodes I1. The primary winding 23 of the transformer I2 is included in the anode supply circuit so that variations in the anode current due to demodulation of the incoming signals may be transferred to the secondary winding 24 of the transformer I2. This secondary Winding leads to a bridge member 20 and thence to the anodes II of the transmitting oscillator tube 6. A transmitting antenna of the dipole type is shown connected with the anodes and having radiating arms I8. The complete system as shown in Fig. 2 may be readily understood by those skilled in the art to be representative of an ultra-high frequency twoway radio apparatus. While the receiving and transmitting portions are shown to be intercoupled, this feature is not essential and, of course, the two portions could be operated independently of one another as in a two-way radio communication system.

Furthermore, both tubes may be arranged to operate on the same wave, so that the transmitter tube 6 causes a damping reduction in the receiver tube 1. When operating with different waves and using the tubes as a relay station any mutual disturbance between the various stations may readily be avoided according to well known methods. On the other hand. the waves of the transmitter and for the receiver may be chosen in such manner that their combination frequency can be utilized in the receiver for superheterodyne reception.

Finally, by means of the arrangement according to the invention, the transmitter may also be separately excited. Thus, it may be desirable to employ the tubes 6 and 'I both as generators and these tubes may be separately excited. A receiver tube may otherwise be arranged between a further pair of pole shoes.

The advantages of the arrangements of the present invention reside in the low weight and simplicity. If between the individual pairs of pole shoes, tubes are placed whose frequency difference it is desired to maintain constant for the purpose of superheterodyne reception or for damping reduction, the working points may be so placed by suitable choice of the plate potentials, that, notwithstanding a variation in the magnetic field strength, all frequencies will be caused to vary upwards or downwards in the same degree, thus retaining the difference between the frequencies.

What is claimed is:

1. A magnetron discharge tube arrangement comprising a plurality of magnetron discharge tubes and their associated circuits, means including separate sets of magnetic pole faces having a common magnetizing winding for producing magnetic lines of force directly through the separate zones of electronic emission in each of said magnetron discharge tubes, and means for independently controlling the field strength applied to the respective magnetron discharge tubes.

2. In a device for relaying signals, a magnetron discharge tube in combination with means for operating the same in response to received signaling energy, a second magnetron discharge tube arranged to operate as an oscillation generator, the first said tube having an anode output circuit which includes the primary winding of a transformer and the second said tube having an anode circuit which includes the secondary winding of the same transformer, and magnetic flux concentrating means common to the two said tubes.

3. Apparatus in accordance with claim 2 and further characterized in that the two magnetron discharge tubes are caused to operate at different frequencies.

4. Two-way radio apparatus comprising a demodulator having a magnetron discharge tube responsive to incoming signals, a magnetron discharge tube oscillator, means for modulating the output energy from said oscillator with output energy from said demodulator, means common to the demodulator and the oscillator for magnetizing the electron discharge zones thereof, and means for independently varying the magnetic flux through each of said discharge tubes.

5. Two-way radio apparatus according to claim 4 and having responsive means of the rotating coil type disposed within the zone of influence of said magnetizing means, whereby the weight of said apparatus is minimized.

6. Radio relay apparatus comprising a demodulator having a magnetron discharge tube responsive to incoming signals, a magnetron discharge tube oscillator, means for modulating the output energy from said oscillator by the output energy from said demodulator, and means common to the demodulator and the oscillator for magnetizing the electron discharge zones thereof whereby the weight of said apparatus is minimized.

7. Radio apparatus comprising a plurality of magnetron discharge tubes, coupling circuits whereby output energy from one of said tubes may be caused to influence the operation of another of said tubes, and means common to all of said tubes for magnetizing the electron discharge zones thereof, whereby the weight of said apparatus is minimized.

8. Radio apparatus according to claim 7 and having an electrical indicating instrument comprising a moving coil positioned within the zone of influence of said magnetizing means, whereby the weight of said apparatus is minimized.

ERNST GERHARD. 

